This invention relates to a food-preserving agent and a method for preserving food with the food-preserving agent, and more particularly to a food-preserving agent capable of removing acetaldehyde and a method for preserving food with the said food-preserving agent.
Heretofore, methods for preserving food in sealed packages, based on a vacuum treatment or replacement with an anaerobic gas such as a nitrogen gas, etc. have been developed. More recently, methods for preserving food in sealed packages, based on filling with an oxygen absorbent, ethanol vapors, or an ethanol-transpiring agent, or a combination thereof have been proposed.
Particularly, methods for preserving food in sealed packages based on simultaneous use of an oxygen absorbent and ethanol vapors or an ethanol-transpiring agent have been regarded as one of ideal methods for preserving food, because the former is effective for the control of aerobic bacteria and the latter is effective for the control of anaerobic bacteria.
However, it has been found that these methods have a problem, that is, generation of acetaldehyde by contact of ethanol vapors or liquid with an oxygen absorbent and the resulting oxidation of ethanol. Furthermore, it has been found that the generation of acetaldehyde is not only due to the simultaneous use of the oxygen absorbent and ethanol, but also due to food itself, as disclosed in Japanese Patent Application Kokai (Laid-open) No. 62-40273. The generated acetaldehyde itself is a substance causing a disagreeable odor, and its toxicity also is a problem.
Practical steps for removing the generated acetaldehyde rapidly have been required to develop and thus extensively investigated. As a result, the following substances have been so far proposed to remove the acetaldehyde, in Japanese Patent Application Kokai No. 61-285973 and 62-40273 et al.
(1) Ammonium salts such as ammonia alum, ammonium sulfate, etc. PA1 (2) Urea PA1 (3) Amino acids such as lysin, arginine, glycine, glutamine, etc. PA1 (4) Proteins such as albumen, casein, gluten, etc. PA1 (5) Peptides such as peptones, gelatin, etc. PA1 (6) Inorganic alkali metal hydroxides such as sodium hydroxide, etc. PA1 (7) Sulfites such as sodium sulfite, etc. PA1 (8) Bisulfites such as sodium bisulfite, etc. PA1 (9) Thiosulfates such as sodium thiosulfate, etc. PA1 (10) Sulfates such as sodium sulfate, etc. PA1 (11) Aromatic aminosulfonic acids, their alkali metal salts and alkaline earth metal salts such as sulfanilic acid, sodium sulfanilate, etc. PA1 (12) Weakly basic ion exchange resins
The substances (1) and (2) are preferable with respect to the safety and cost, but have a problem in the ability to remove acetaldehyde. The substances (3) to (5) alone have also a problem in the ability to remove acetaldehyde, and must be used actually together with a toxic alkaline substance, as disclosed, for example, in Japanese Patent Application Kokai (Laid-open) No. 62-40273, and also have such a problem that they are disagreeable odor sources by themselves. The substances (6) to (11) are highly toxic by themselves and also have such a problem that they are disagreeable odor sources. The substance (12) is high in the cost and also has such a problem as an amine odor.